1. Field of the Invention
The invention relates to a barcode reading method, and in particular to a barcode reading method and device, providing automatic focus adjustment.
2. Description of the Related Art
It is mostly commonly seen that barcodes are types of transactions and administration ways on commodities, which are utilized to record data of commodity items and selling prices. After a barcode on a commodity is scanned and decoded by a barcode reader, data of this scanned commodity is obtained and various subsequent processes and operations related to this commodity can be executed.
A conventional barcode reader includes an image sensor that is capable of capturing an image via a lens. An image of the barcode can be captured by the image sensor when the barcode is scanned, and image data corresponding to the barcode can be produced for recognition.
However, in the present barcode readers, the distance between the image sensor and the lens is fixed. Thus, a whole image of the barcode fails to form on the image sensor unless the barcode is sufficiently close to the lens. If the barcode and the lens have a longer distance therebetween, the barcode possibly cannot be clearly imaged on the image sensor, and consequently the correctness and success rate of the subsequent barcode recognition cannot be acquired. Moreover, the barcodes with various formats in the present market even increase complexity of readability of barcodes.